CVE-2026-64151 iommupt: Check for missing PAGE_SIZE in the pgsize_bitmap
A logic error in the Linux kernel IOMMU page table code could lead to undefined behavior if PAGE_SIZE is missing from the bitmap, though currently unexploitable.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64151?
CVE-2026-64151 is a high-severity vulnerability in Linux kernel, published on 19 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
iommupt: Check for missing PAGE_SIZE in the pgsize_bitmap
Sashiko pointed out that the driver could drop PAGE_SIZE from the pgsize_bitmap. That is technically allowed but nothing does it, and such an iommu_domain would not be used with the DMA API today.
Still, it is against the design and it is trivial to fix up. Lift the PT_WARN_ON to the if branch and just skip the fast path.
Which versions are affected by CVE-2026-64151?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64151?
Apply the vendor's patch.
Is CVE-2026-64151 being exploited?
There is no known exploitation of CVE-2026-64151 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2026-64151, GHSA-953v-7jq6-jh93, UBUNTU-CVE-2026-64151.